A new power supply only costs about £14,tiz a good bet that is the culprit,neigbors had simiar probs last week fans running but buggah all else occuring,have a spare PSU disconected all the leads tried my spare on it without putting it in the case and everything worked fine,just because the fan is running dont mean the power supply is ok,he bought a new PSU the next day and I stuck it in for him,and if it is not that, you always have a spare.
Power supplies are buggas to test out of the case unless you know what pins to short out they will just sit on the table plugged in and switched on doing nowt.
